A conventional image forming apparatus comprising a printing head that ejects ink is known (for example, see Patent Literature 1).
Patent Literature 1 discloses an image forming apparatus comprising a printing head, a lead screw, and a wiper member and cap-lifting mechanism installed to the lead screw so as to move in an axial direction by a rotation of the lead screw. The wiper member and the cap-lifting mechanism are configured to be continuously threaded to the lead screw and to move on the same lead screw independently of each other.
The lead screw includes a first grooved portion formed with a spiral groove with a large pitch provided in a central portion and second grooved portions formed with a spiral groove with a small pitch provided on both end-portion sides of the first grooved portion. The wiper member is configured to wipe ink adhered to an ejecting surface of the printing head. The cap-lifting mechanism includes a cap member that covers the ejecting surface of the ink of the printing head. Moreover, the cap-lifting mechanism is configured to separate the cap member from the ejecting surface (lower the cap member) in conjunction with moving the first grooved portion with the large pitch. Therefore, the cap-lifting mechanism is configured to move the first grooved portion with the large pitch independently ahead of the wiper member for the wiper member to wipe the ink of the ejecting surface.
Specifically, in a standby state, the wiper member and the cap-lifting mechanism are disposed near each other and are both disposed in a state of being threaded to one of the second grooved portions with the small pitch. Moreover, the cap-lifting mechanism is disposed more on a first-grooved-portion-with-the-large-pitch side of the lead screw than the wiper member. Moreover, the cap-lifting mechanism separates from the wiper member that moves in the second grooved portion with the small pitch by independently moving in the first grooved portion by being threaded to the first grooved portion with the large pitch from the second grooved portion with the small pitch, and the cap member separates from the ejecting surface. While the cap-lifting mechanism is performing the separating operation from the ejecting surface, the wiper member moves in the second grooved portion with the small pitch; after the separating operation of the cap-lifting mechanism from the ejecting surface is ended, a wiping operation of the ink by the wiper member is performed by the wiper member moving by being threaded to the first grooved portion with the large pitch from the second grooved portion with the small pitch.